Mobile phones have become very common. Unfortunately, also the thefts of mobile phones have become more common. A thief may seek for use of the phone, to resell the phone for money and/or access to content within a phone. For the owner, the phones are personal items because of various sensitive private data they contain. Mobile phones are also being equipped with ever larger memories and often contain emails, short messages, calendar entries, phone books, call logs, photos and video clips taken by the phone, physical exercise diaries, shopping lists, and even online banking credentials.